MSCAGR (Plant Production) / Department of Plant Production / Tepary bean (Phaseolus acutifolius) is an important food legume originating from South America and the South-western parts of the United States. The crop is produced in many countries worldwide including South Africa. It is highly tolerant to drought and the seed contains a wide range of vitamins, minerals and protein of high nutritional quality. The genetic base of tepary bean is narrow but can be widened by chemical mutagenesis. However, there are no reports on the impact of chemical mutagenesis on the root nodulation and seed storage proteins in tepary bean. Therefore, this study was designed to examine root nodulation attributes and seed storage proteins of three tepary bean genotypes in the early mutagenic generations (M2 to M4) derived through treatment with varying doses (0.0, 0.5, 1.0, 1.5 and 2.0 v/v) of ethyl methanesulfonate (EMS). The experiment on root nodulation attributes was laid out as a 3 x 5 x 3 (genotypes x EMS doses x mutant generations) factorial design replicated three times. At harvest, shoot height (SHT), primary root length (PRL), dry weights (shoot, root and nodule), number of nodules per plant (NNP) and grain yield components such as the number of pods per plant (NPP) and number of seeds per pod (NSP) were measured. Highly significant (P≤0.01) dose effects were observed for SHT, PRL, shoot dry weight (SDW) and root dry weight (RDW). Highly significant (P≤0.01) interaction effects of mutant generation x genotype x dose were observed for NSP. A highly significant (P≤0.01) positive linear relationship was observed between the NNP and nodule dry weight (NDW). Increase in the PRL suggested that tepary bean mutants could be important in drought tolerance. EMS treatment led to an enhanced partitioning of dry matter (assimilates) to the shoots and roots. There was a three fold increase in most of the root nodulation traits at the 0.5% EMS dose.The Kjeldahl method was used for crude protein determination whereas the sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS PAGE) was utilized in determining the protein banding patterns of the bean. There were highly significant (P≤0.01) differences among the genotypes in crude protein accumulation. Highly significant (P≤0.01) mutant generation x genotype x dose were observed for seed protein accumulation. ‘Genotype 3’ attained the highest protein content (24.23%) at 1.5% EMS dose in the M4 generation. EMS doses ≥0.5% positively stimulated protein accumulation in all genotypes but high EMS doses (2.0%) depressed protein content. There were significant variations in seed storage protein profiles among the genotypes and mutant generations. ‘Genotype 6’ showed a distinct 15.0kDa protein fragment which was absent in the majority of the remaining genotypes. The presence of distinct protein subunits in the three genotypes could be used in varietal / NRF

Master of Agribusiness / Department of Agricultural Economics / Vincent Amanor-Boadu / Beans and cowpeas are considered nutritionally dense and good sources of protein. In this sense, they are considered excellent food in poor households, especially in those that exhibit high levels of malnutrition or under-nutrition. To address food security and nutrition security in poor countries, there has been an increasing interest in encouraging farmers to grow beans and cowpeas. This has spurred research in value chains for these crops in many countries, especially those that do not traditionally grow them as primary staples. Most of these research efforts have focused on the producer and consumer issues, with little or no attention paid to traders who operated between these two players in the value chain. The objective of this study, therefore, is to contribute to the literature on the bean and cowpea value chain research by identifying the factors influencing the participation decisions of traders in this segment of the agricultural economy in Zambia. Using data collected by the Pulse Value Chain Initiative – Zambia in 2011, a probit model was used to analyze data. The dependent variable trader participation in wholesale marketing of beans and cowpeas in Lusaka and its principal food markets. The explanatory variables encompass trader demographic characteristics and available assets or resources. The research explored the effect of the assets or resources on the choice to trade cowpeas or beans at the wholesale level in Lusaka with and without controlling for traders’ demographic characteristics. Three procurement sources are identified in the study: the local market within which the traders operate; producers/suppliers within Lusaka District; and producers/suppliers outside Lusaka District. The results indicate that the procurement source for beans and cowpeas influenced trader decision to operate at the wholesale level. For example, traders who purchased their produce from locations outside Lusaka District were about 37% more likely to participate in wholesale trade compared to those sourcing their produce within the market in which they operate when demographic characteristics of traders are not controlled for in the model. When the demographic factors are controlled, the likelihood of those procuring from outside Lusaka District participating in the wholesale trade declines slightly to about 34%. These coefficients were both statistically significant at the 1 percent level. The results also showed that traders using credit from friends and family were nearly 18% less likely to participate in wholesale trade than those borrowing from other traders, significant at the 5% level. Controlling for demographic characteristics led to a reduction of this likelihood to about 16.7%, significant only at the 10% level. There were no statistical differences between traders for all education levels and those without any education except for respondents with lower primary and lower secondary education. Traders with lower primary and lower secondary education had a 31% higher likelihood of operating at the wholesale level compared to those without any formal education while those with upper secondary education had about 26.7% higher likelihood of operating at the wholesale level compared to those without any formal education. Marital status was not a discriminant in the decision to operate at the wholesale level. However, males had about a 9% higher probability than females in operating at the wholesale level. Wholesalers tend to move larger volumes of produce and, hence, create wealth much quickly than retailers. Wholesalers are also more likely to be engaging processors when these exist in the supply chain. Given that traders sourcing their produce from outside Lusaka District are more likely to engage in wholesale trading, it recommended that further research into the intricate characteristics of these traders are explored. This future research will do well to explore the factors that specifically differentiate these traders from the others. Understanding these and their potential effects could allow policymakers to provide support and services to this class of traders to engage in structured relationships with larger organizations such as processors and exporters.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

LD2668 .T4 1954 T64 / Master of Science

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The dry matter (DM) production and chemical composition of whole crop faba beans (Vicia faba) and oats (Avena sativa) were determined according to fresh material harvested at weekly intervals. From 75 to 166 days after planting whole plants of faba beans and oats were harvested at a height of ca. 10 cm above the ground on five randomly selected areas of 0.25 m² each. The freshly harvested material was weighed “as is” and ovendried to determine the DM content of each sample. The fresh and DM forage production per hectare was then calculated. The crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen free extract (NFE), fat (EE), calcium (Ca) and phosphorus (P) contents were determined according to standard laboratory techniques. The change in chemical composition of fresh whole crop material was regressed on days after planting using simple linear regressions. The fresh and DM production of whole crop faba beans and oats increased with advancing growth stage. During the 2002 production year fresh yield production of both whole crop faba beans and oats peaked at 131 days (44.7±6.9 and 28.4±7.1 ton/ha respectively). DM yield peaked at 159 and 152 days for whole crop faba beans and oats being 9.4±1.3 and 8.8±0.7 tons DM/ha respectively. The chemical composition of both forage crops decreased with advancing growth stage. The CP content of whole crop faba beans decreased (P<0.05) from 25.3% at 82 days after planting to 18.4 % at 166 days after planting in the 2002 production year, while during the 2003 production year the CP content of whole crop faba beans decreased (P<0.05) from 28.2 to 19.5 % from 75 to 159 days after planting. During 2002 the CF % of faba beans increased from 20.2 to 22.6%, while during 2003 CF % similarly increased from 21.8 to 26.5%. The CF % for oats during 2003 increased from 25.6 to 36.9%. During the same time the EE, Ca and P contents also decreased (P<0.05), while the NDF, CF and ADF contents increased (P<0.05). Two milk production studies were conducted to compare the feed intake, milk yield and milk composition of Holstein cows receiving either whole plant faba bean silage or oats as a hay or silage. Faba bean (Vicia faba) silage (FBS) was compared to that of cows receiving either oat (Avena sativa) hay (OH) or oat silage (OS) and in a 50:50 combination with FBS. Faba beans (cv. Ascot) and oats (cv. Sederberg) were planted on a Glenrosa soil. Whole crop faba beans were ensiled 145 days after planting in an above ground concrete bunker using a commercial bacterial inoculant after being wilted for one day. In the first experiment, total mixed rations (TMR) containing FBS, OH or a 50:50 mixture of FBS and OH as forage, together with a concentrate, were fed to three groups of seven lactating Holstein cows each. The experiment was conducted according to a randomized block design. Cows were on average 112±44 days post calving producing 24.0±6.2 kg milk/day. Milk production parameters of cows receiving diets containing different forages were compared by analysis of variance. The DM intake and milk yield of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OH as forages did not differ (P>0.05), milk yields being 18.9±1.9, 20.6±1.3 and 20.5±1.4 kg/cow/day respectively. With the exception of MUN, milk composition parameters did not differ among treatments (P>0.10). Cows fed OH as roughage source had a higher (P=0.06) MUN level in the milk. Results from this study indicate that FBS could effectively replace OH in lactating dairy cow diets. In the second experiment, total mixed rations (TMR) containing FBS, oat silage (OS) or a 50:50 mixture of FBS and OS as forages, together with a concentrate, were fed to six Holstein cows according to a double 3 x 3 Latin Square cross-over experimental design. Each cow received 13 kg DM either FBS, OS or a 50:50 mixture of FBS and OS were fed as forages, together with three different concentrates at nine kg “as is” each, to each cow. Cows were on average 108±30 days post calving producing 22.0±2.0 kg milk/day. DM intake, body weight, milk yield and milk composition parameters of cows receiving diets containing different forages were compared statistically. The DM intake and body weight of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), although body weight changes differed significantly (P<0.10), i.e. 4.0±3.2, 8.8±3.2 and -6.0±3.2 kg respectively. The milk yield of cows receiving TMR’s containing FBS, OS or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), milk yields being 22.8±0.4, 21.4±0.4 and 21.9±0.4 kg/cow/day respectively. Of the milk composition parameters, the milk CP(%) of cows fed TMR’s containing FBS differed (P<0.05) from the cows fed the 50:50 mixture of FBS and OS, as well as cows fed the OS, being 2.82±0.02, 2.93±0.02 and 2.96±0.02% respectively. Results from this study indicate that FBS could effectively replace OS in lactating dairy cow diets. The South African database on in situ protein and fiber degradability values for whole crop faba beans and oats is limited. The chemical composition of whole crop faba beans and oats constantly change as plants mature. For optimal stage of ensiling and feed formulation it would be useful to have CP, NDF and ADF degradability values available for whole crop faba beans and oats harvested at different growth stages. The objective of this study was to determine the ruminal nutrient degradabilities of whole crop faba beans (Vicia faba) and oats (Avena sativa). Whole crop faba beans and oats were cut at weekly intervals from 75 to 159 days after planting. Effective DM, CP, NDF and ADF degradability values of faba beans and oats harvested at 117, 131, 145 and 159 days after planting were determined by using the in situ nylon bag technique. Three non-lactating Holstein cows fitted with ruminal fistulae were used. Plant material put into Dacron bags was incubated in the rumen for 4, 8, 12, 24, 48, 72 and 96 hours. The degradability of DM, CP, NDF and ADF fractions of whole plant faba beans and oats in four different growth stages (117, 131, 145 and 159 days from planting) did not differ (P<0.05) among cows. The degradability of different fractions for both roughages were affected (P<0.05) by growth stage and incubation hours. DM, CP, NDF and ADF disappearance of whole crop faba beans and oats at 117 and 159 days after planting differed (P<0.05) at 4, 8, 12, 24, 48, 72 and 96 hours of incubation time. The DM, CP, NDF and ADF disappearance values were fitted to the non-linear model p = a + b (1- e-ct). The effective degradabilities (P) could be calculated using a fractional outflow rate of k = 0.05. For whole crop faba beans, parameter b (potentially degradable fraction) and parameter c (the rate at which b is degraded) all differed different forages were compared by analysis of variance. The DM intake and milk yield of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OH as forages did not differ (P>0.05), milk yields being 18.9±1.9, 20.6±1.3 and 20.5±1.4 kg/cow/day respectively. With the exception of MUN, milk composition parameters did not differ among treatments (P>0.10). Cows fed OH as roughage source had a higher (P=0.06) MUN level in the milk. Results from this study indicate that FBS could effectively replace OH in lactating dairy cow diets. In the second experiment, total mixed rations (TMR) containing FBS, oat silage (OS) or a 50:50 mixture of FBS and OS as forages, together with a concentrate, were fed to six Holstein cows according to a double 3 x 3 Latin Square cross-over experimental design. Each cow received 13 kg DM either FBS, OS or a 50:50 mixture of FBS and OS were fed as forages, together with three different concentrates at nine kg “as is” each, to each cow. Cows were on average 108±30 days post calving producing 22.0±2.0 kg milk/day. DM intake, body weight, milk yield and milk composition parameters of cows receiving diets containing different forages were compared statistically. The DM intake and body weight of cows receiving TMR’s containing FBS, OH or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), although body weight changes differed significantly (P<0.10), i.e. 4.0±3.2, 8.8±3.2 and -6.0±3.2 kg respectively. The milk yield of cows receiving TMR’s containing FBS, OS or a mixture of 50:50 FBS and OS as forages did not differ (P>0.10), milk yields being 22.8±0.4, 21.4±0.4 and 21.9±0.4 kg/cow/day respectively. Of the milk composition parameters, the milk CP(%) of cows fed TMR’s containing FBS differed (P<0.05) from the cows fed the 50:50 mixture of FBS and OS, as well as cows fed the OS, being 2.82±0.02, 2.93±0.02 and 2.96±0.02% respectively. Results from this study indicate that FBS could effectively replace OS in lactating dairy cow diets. The South African database on in situ protein and fiber degradability values for whole crop faba beans and oats is limited. The chemical composition of whole crop faba beans and oats constantly change as plants mature. For optimal stage of ensiling and feed formulation it would be useful to have CP, NDF and ADF degradability values available for whole crop faba beans and oats harvested at different growth stages. The objective of this study was to determine the ruminal nutrient degradabilities of whole crop faba beans (Vicia faba) and oats (Avena sativa). Whole crop faba beans and oats were cut at weekly intervals from 75 to 159 days after planting. Effective DM, CP, NDF and ADF degradability values of faba beans and oats harvested at 117, 131, 145 and 159 days after planting were determined by using the in situ nylon bag technique. Three non-lactating Holstein cows fitted with ruminal fistulae were used. Plant material put into Dacron bags was incubated in the rumen for 4, 8, 12, 24, 48, 72 and 96 hours. The degradability of DM, CP, NDF and ADF fractions of whole plant faba beans and oats in four different growth stages (117, 131, 145 and 159 days from planting) did not differ (P<0.05) among cows. The degradability of different fractions for both roughages were affected (P<0.05) by growth stage and incubation hours. DM, CP, NDF and ADF disappearance of whole crop faba beans and oats at 117 and 159 days after planting differed (P<0.05) at 4, 8, 12, 24, 48, 72 and 96 hours of incubation time. The DM, CP, NDF and ADF disappearance values were fitted to the non-linear model p = a + b (1- e-ct). The effective degradabilities (P) could be calculated using a fractional outflow rate of k = 0.05. For whole crop faba beans, parameter b (potentially degradable fraction) and parameter c (the rate at which b is degraded) all differed v significantly (P<0.05) between four different growth stages (117, 131, 145 and 159 days from planting) of plant maturity for CP, NDF and ADF. In oats, parameter b and parameter c did not differ (P>0.05) between the four different growth stages (117, 131, 145 and 159 days from planting) of plant maturity. Results from this study could make a valuable contribution towards the South African databases on faba bean and oats nutrient values and can be used in dynamic feed formulation. Faba beans cut as fresh crop or silage may in the foreseeable future play an increasingly larger role in the feeding of dairy cattle in the Winter Rainfall Region of South Africa. As in the case of lupin silage, though with much higher protein content, farmers will be able to produce their own quality and high protein roughage. The nutritive properties of faba bean silage holds great promise as a forage in lactating dairy cows. / AFRIKAANSE OPSOMMING: Die droëmateriaal (DM) produksie en chemiese samestelling van heelplant fababone (Vicia faba) en hawer (Avena sativa) is bepaal deur vars plantmateriaal op ‘n weeklikse basis te sny. Plantmonsters van beide fababoon en hawerplante is gesny vanaf 75 tot 166 dae na plant op ‘n hoogte van ca. 10 cm bo die grond. Plantmonsters is weekliks gesny op vyf ewekansige persele met ‘n oppervlak van 0.25 m² elk. Die vars gesnyde plantmateriaal is geweeg en daarna ge-oonddroog om die DM inhoud van elke monster te bepaal. Die varsmateriaal en DM opbrengs per hektaar is bereken. Die ruproteïen (RP), ruvesel (RV), neutraal bestande vesel (NBV), suur bestande vesel (SBV), stikstof vrye ekstrak (NVE), eterekstrak (EE), kalsium (Ca) en fosfor (P) inhoud is bepaal volgens standaardlaboratorium metodes. Lineêre regressie is gebruik om die verandering in chemiese samestelling van heelplant fababone en hawer te kwantifiseer. Vars en DM produksie van heelplant fababone en hawer het toegeneem met toename in groeistadium. Gedurende die 2002 produksiejaar het varsmateriaal opbrengs vir beide fababone en hawer gepiek op 131 dae (44.7±6.9 en 28.4±7.1 ton/ha respektiewelik). Heelplant fababoon en hawer DM opbrengs het gepiek op 159 en 152 dae na plant op 9.4±1.3 en 8.8±0.7 ton DM/ha, respektiewelik. Die chemiese samestelling van beide gewasse het afgeneem met toename in groeistadium. Die RP inhoud van heelplant fababone het verminder (P<0.05) van 25.3% op 82 dae na plant tot 18.4% op 166 dae na plant vir die 2002 produksiejaar, terwyl gedurende die 2003 produksiejaar die RP inhoud verminder (P<0.05) het vanaf 28.2 tot 19.5% vanaf 75 tot 159 dae na plant. Gedurende die 2002 produksiejaar het die ruvesel % van fababone toegeneem vanaf 20.2 tot 22.6%, terwyl gedurende die 2003 produksiejaar het die ruvesel toegeneem vanaf 21.8 tot 26.5%. Die ruvesel % vir heelplant hawer het vir die 2003 produksiejaar toegeneem vanaf 25.6 tot 36.9%. Vir dieselfde tyd, het EE, Ca en P inhoud ook verminder (P<0.05), terwyl NBV, RV en SBV inhoud toegeneem (P<0.05) het. Twee melkproduksiestudies is uitgevoer om die effek van fababoonkuilvoer op voerinname, melkopbrengs en melksamestelling van Holsteinkoeie te bepaal. Fababoonkuilvoer (FBKV) is vergelyk met behulp van koeie wat hawerhooi (HH) of hawerkuilvoer (HKV) en in ‘n 50:50 kombinasie met FBKV as ruvoere ontvang het. Fababone (cv. Ascot) en hawer (cv. Sederberg) is gevestig op ‘n Glenrosa grond. Heelplant fababone is gesny en ingekuil op 145 dae na plant. Gesnyde materiaal is toegelaat om vir ‘n dag te verlep, waarna dit in ‘n bogrondse kuilvoersloot ingekuil is met behulp van ‘n kommersiële bakteriële entstof. In die eerste eksperiment is volvoere met FBKV, HH en ‘n 50:50 mengsel van FBKV en HH as ruvoer, saam met ‘n konsentraat, gevoer aan drie groepe koeie wat bestaan het uit sewe Holsteinkoeie elk. Die eksperiment is uitgevoer volgens ‘n ewekansige blokontwerp. Koeie was gemiddeld 112±44 dae in melk en het 24.0±6.2 kg melk/dag geproduseer. Melkproduksie-veranderlikes van koeie wat diëte ontvang het met verskillende ruvoere is met ‘n variansie-analise vergelyk. Die DM inname en melkopbrengs van koeie op volvoere bevattende vii FBKV, HH of ‘n 50:50 mengsel van FBKV en HH, het nie betekenisvol verskil (P>0.05) nie. Melkopbrengs was 18.9±1.9, 20.6±1.3 en 20.5±1.4 kg/koei/dag, respektiewelik. Met die uitsondering van melkureumstikstof (MUN), het melksamestelling-veranderlikes nie betekenisvol (P>0.10) verskil tussen behandelings nie. Koeie wat HH as ruvoer ontvang het, het ‘n hoër (P=0.06) MUN vlak in die melk gehad. Resultate van hierdie studie dui daarop dat FBKV effektief HH in lakterende melkkoeidiëte kan vervang. In die tweede eksperiment is volvoere, betsaande uit FBKV, hawerkuilvoer (HKV) of ‘n 50:50 mengsel van FBKV en HKV as ruvoer, saam met ‘n konsentraat aan ses Holsteinkoeie gevoer volgens ‘n dubbel 3 x 3 Latynse Vierkant omskakel proefontwerp. Elke koei het 13 kg DM van FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV ontvang as ruvoere, saam met drie verskillende konsentrate van 9 kg op ‘n natuurlike vogbasis elk. Koeie was gemiddeld 108±30 dae in melk en het 22.0±2.0 kg melk/dag geproduseer. DM inname, liggaamsmassa, melkopbrengs- en melksamestelling- veranderlikes van koeie op verskillende diëte wat verskillende ruvoere ingesluit het, is statisties vergelyk. Die DM inname en liggaamsmassa van koeie op volvoere bevattende FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV, het nie betekenisvol (P>0.10) verskil nie. Verandering in liggaamsmassa het betekenisvol (P<0.10) verskil, te wete 4.0±3.2, 8.8±3.2 en -6.0±3.2 kg, respektiewelik. Die melkopbrengs van koeie op volvoere bevattende FBKV, HKV of ‘n 50:50 mengsel van FBKV en HKV as ruvoer, het nie verskil (P>0.10) nie. Melkopbrengs was 22.8±0.4, 21.4±0.4 en 21.9±0.4 kg/koei/dag, respektiewelik. Ten opsigte van die melksamestelling-veranderlikes van die koeie op die onderskeie volvoere, was dit slegs melk RP(%) van koeie wat volvoere met FBKV ontvang het, wat betekenisvol (P<0.05) verskil het van die koeie wat HKV en die 50:50 mengsel van FBKV en HKV as ruvoer ontvang het. Melk RP(%) was 2.82±0.02, 2.93±0.02 en 2.96±0.02%, respektiewelik. Resultate van hierdie studie dui daarop dat FBKV effektief HKV in lakterende melkkoei diëte kan vervang. Die Suid-Afrikaanse databasis van in situ proteïen- en veseldegradeerbaarheidswaardes vir heelplant fababone en hawer is beperk. Die chemiese samestelling van heelplant fababone en hawer verander gedurig soos plante toeneem in ouderdom en groeistadium. Vir optimale stadium van inkuiling en voerformulering sou dit belangrik wees om DM, RP, NBV en SBV degradeerbaarheidswaardes van heelplant fababone en hawer ge-oes op verskillende groeistadiums te hê. Die doel van die studie was om die ruminale degradeerbaarheidswaardes vir heelplant fababone en hawer te bepaal. Effektiewe DM, RP, NBV en SBV degradeerbaarheidswaardes is vir fababone en hawer bepaal vir groeistadiums 117, 131, 145 en 159 dae na plant deur gebruik te maak van die in situ nylon sakkie tegniek. Drie nie-lakterende Holsteinkoeie elk toegerus met ‘n rumen- kannula is gebruik om ruminale degradeerbaarheidswaardes te bepaal. Plantmateriaal wat in Dacron sakkies afgeweeg is, is in die rumen geplaas vir 4, 8, 12, 24, 48, 72 en 96 ure. Die degradeerbaarheid van DM, RP, NBV en SBV fraksies van heelplant fababone en hawer vir vier verskillende groeistadiums (117, 131, 145 en 159 dae na plant) het nie betekenisvol (P<0.05) tussen koeie verskil nie. Die degradeerbaarheid van verskillende fraksies van beide ruvoere het verskil (P<0.05) tussen groeistadiums en inkubasie-ure. DM, RP, NBV en SBV verdwyning van heelplant fababone en hawer op 117 en 159 dae na plant het betekenisvol (P<0.05) verskil by 4, 8, 12, 24, 48, 72 en 96 inkubasie-ure. Die DM, RP, NBV en SBV verdwyningswaardes is gepas op ‘n nie-lineêre model p = a + b (1- e-ct). Die effektiewe degradeerbaarheid (P) kon bereken word met ‘n fraksionele uitvloeitempo van k = viii 0.05 vanuit die rumen. Vir heelplant fababone het parameter b (potensieel degradeerbare fraksie) en parameter c (die tempo waarteen b degradeer word) betekenisvol verskil (P<0.05) vir alle groeistadiums (117, 131, 145 en 159 dae na plant) vir degradeerbaarheidswaardes van RP, NBV en SBV. Vir hawer het parameter b en parameter c nie betekenisvol (P>0.05) tussen die vier verskillende groeistadiums (117, 131, 145 and 159 dae na plant) verskil nie. Die resultate van hierdie studie kan ‘n belangrike bydrae maak tot die Suid-Afrikaanse databasis van fababoon en hawer voedingswaardes, en kan aangewend word in dinamiese voerformulering. Die gebruik van varsgesnyde of ingekuilde heeplant fababone kan in die toekoms ‘n al groter rol speel in melkkoeivoeding in die Winterreënstreek van Suid-Afrika. Soos in die geval met lupiene, maar met ‘n hoër proteïen inhoud, sal produsente hul eie kwaliteit en hoë proteïen ruvoer kan verbou. Die voedingswaarde van fababoonkuilvoer hou groot belofte in as ruvoer vir lakterende melkkoeie.

Two accessions of tepary (phaseolus acutifolius Gray var. latifolius) and navy (P. vulgaris L. 'Fleetwood') beans were studied for salt tolerance at several• developmental stages. Genotypes were germinated at 0.0 through -2.5 MPa NaCl at 25°C and 35°C for nine days. Tepary accessions had higher germination percentages and rates than navy for ≤ - 2.0 MPa at 250C and ≤ - 1.5 MPa at 35°C. Fresh weights of root plus hypocotyl decreased severely with the first increment of NaCl (-0.5 MPa) for all genotypes. Fresh weight of navy was reduced more at 35°C than at 25°C. Genotypes were stressed in vermiculite-filled trays with 0.0 through -1.5 MPa NaCl for 14 days. Final growth stage and rates of emergence were reduced at salinities ~ -0.6 MPa NaCl, and were higher in tepary than navy at -1.2 MPa. Tepary beans tended to maintain higher water and osmotic potentials, and at -0.9 MPa had less reduction in leaf area than navy beans. Fresh weights, dry weights and root:shoot ratios declined in all genotypes with increasing salinities. Plants grown hydroponically were stressed with -0.10, -0.25, and -0.50 MPa NaCl during either vegetative or reproductive stages. Navy had equal or greater fresh and dry weights of leaf, stem, and pods at -0.10 MPa, but tepary beans had equal or greater weights at the highest salinity relative to navy. Tepary had the greatest pod weight with -0.50 MPa NaCl applied during the reproductive stage. Carbon exchange rates (CER) were lower in navy than one or both tepary beans at some sampling times. Tepary beans tended to have higher leaf water and osmotic potentials than did navy. Transpiration and stomatal resistance values were similar in all genotypes, while leaf temperatures were different in white tepary versus navy. Tepary beans yielded higher than navy when grown in low and high salinity fields. Transpiration rates, leaf water and osmotic potentials, and CERs were similar or higher, while stomatal resistance and leaf temperatures were similar or lower in tepary than in navy. Plant height and stand count also were measured. Tepary was more salt tolerant than navy, exhibiting greater tolerance to NaCl at every growth stage.

Shoot and root fresh and dry weight, shoot length, leaf area, leaf area index and relative growth rate of 14 day old tepary bean (Phaseolus acutifolis Gray) and navy bean (Phaseolus vulgaris L.) seedlings were reduced following treatment with NaCl solution exhibiting osmotic potential of either -0.25, 0.50, and -0.75 MPa. Salinity reduced the growth of navy bean more than tepary bean. The physiological basis of the adaptive response of tepary bean seedlings to salt stress was explored by determining the water and osmotic potentials, relative water content, free amino acid and sugar concentrations, distribution and levels of inorganic ions within the seedlings and ATPase activity of the root plasma membrane. Salinity led to an osmotic adjustment in the leaves and the proximal part of the root of tepary bean. Turgor remained almost constant whereas osmotic and water potential and relative water content declined following the salt treatments. The osmotic adjustment of the leaves and proximal part of the roots was -1.7 MPa and -1.2 MPa, respectively, in seedlings treated with -0.75 MPa NaCl solution. Free amino acids and sugars increased under salinity stress in both species but they increased more in the tepary bean. Glucose was the most abundant free sugar. The nonstructural carbon solutes contributed -0.15 MPa to the seedling's osmotic adjustment whereas Na, Cl, K and Ca ion levels contributed -0.85 MPa. However, the levels of these solutes were not large enough to account for the total osmotic adjustment observed in the salt treated seedlings. This study shows that tepary bean has specific strategies to overcome the impact of salinity through osmotic adjustment and exclusion of Na and Cl ions from the stems and leaves by retaining these ions in the proximal part of root and stem base. (Abstract shortened with permission of author.)

Results of the 1994 National Cooperative Dry Bean Nursery Trials are reported in this report Thirty two varieties of eight different classes of beans were included in this replicated, small plot trial Bill-Z, the leading pinto bean variety in the area, was the highest yielding variety with a yield over 4200 pounds per acre. Chase, a pinto variety recently developed with strong rust tolerance, yielded over 4000 pounds per acre. Yields, seed per pound, days to bloom, seed fall duration and yield per day of seed fill are reported in this paper.

Lesquerella is a potential crop plant that produces seeds containing hydroxy fatty acids similar to those in castor beans. An important step in the commercialization of this plant for Arizona farms is the development of an efficient agronomic production system. Research on planting dates and nitrogen fertility was conducted at the Maricopa Agricultural Center in the 1991-92, 1992-93, and 1993-94 seasons. Results of the Planting date experiments indicate that early fall planting dates are superior to late fall planting dates in terms of seed yield February plantings appear to be too late for central Arizona production. In all years, lesquerella responded to nitrogen (N) fertilizer. In the 1993-94 test, an application of 54 lbs. N/acre gave a higher seed yield than when no N was applied and the same yield as 108 lbs. N/acre. Additional tests are being conducted to determine optimum timing for N fertilizer applications.

Lesquerella is a plant that grows in the wild in southwestern U.S. and produces seeds containing hydroxy fatty acids similar to those in castor beans. Research has indicated that lesquerella has potential as a crop plant for Arizona. An important step in the commercialization of this plant for Arizona farms is the development of an efficient agronomic production system. Research to determine the effect of nitrogen (N) rates and timing of N applications on lesquerella production was conducted at the Maricopa Agricultural Center in the 1993 -94 and 1995 -96 seasons. Nitrogen application rates of 0 to 108 and 0 to 162 lbs. N /acre were evaluated in 1993 -94 and 1995 -96 tests, respectively. Seed yields as high as 1780 lbs. /acre were obtained in the 1995 -96 test using a conventional combine for harvest. In both tests, lesquerella biomass production and seed yields increased as the N rate was increased. In 1995 -96, a split application of N in March and April resulted in higher seed yields than a single application in March. Seed oil content decreased in both tests as the N rate was increased. In 1995 -96, seed oil content decreased 12% as the N rate was increased from 0 to 162 lbs. N /acre. The N application rate had no effect on 1000 -seed weight.