Thesis (MScAgric (Agronomy))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: Little is known about the nutrient requirements of broccoli grown for seed production. During 2006
and 2007 broccoli were grown for seed production in sand bags in a net structure, using a drain to
waste hydroponic system. The experimental design was a randomized complete block with
seven treatments replicated in four blocks. In 2006 seven nutrient solution treatments were
tested. The Standard solution based on Steiner’s universal solution was compared with different
levels of N, S, K and Ca with regard to the effect on total biomass, nutrient concentration, nutrient
assimilation, seed yield and quality. No significant differences in total biomass produced were
found. Total dry mass increased by 225% from the mature head stage until harvest of seed.
Nutrient concentration in plant samples were not influenced by treatments except where low
levels of K and S in nutrient solutions led to significantly lower levels of K and S concentrations.
The total assimilation of elements were calculated to determine the effect of the much longer
growth period needed for seed production in comparison to normal head production on nutrient
requirements. Major elements assimilated ha-1 was: N 173.0 kg, P 35.5 kg, K 348.4 kg, Ca 114.7
kg, Mg 30.5 kg, S 42.2 kg.
The seven treatments used during 2007 included three of the treatments which were used in 2006
as well as treatments with foliar sprays containing Ammonium Nitrate and Calcium Metalosate.
The standard solution treatment was also used in 2007 to compare results with 2006. Plant
analysis done on plants from the standard solution (2006 & 2007) showed similar trends. As the
plants developed towards maturity there was a relative increase in concentration in the top plant
parts (pods, flowers and stems) for Ca, Mg and S. Contrary, N and P concentration declined.
The minor elements, Fe, Mn and B also increased in concentration in the top plant parts at
harvest indicating a strong relative flow of these elements to the top plant parts towards
maturation. Concentration values of major elements in plant samples were generally different
when the two years were compared. Element concentrations in the seed pods were in general
higher than in the rest of the plant indicating the pods as a strong sink on the plants.
During both years the two best nutrient solutions for yield were the same, namely the Standard
solution and Standard - K which contain low levels of K. During 2006 no significant differences in
seed quality were found. During 2007 no significant differences were found for seed quality
measurements, except for size (of the cotyledons). The results indicate that no special
adjustments need to be made to the Standard solution in order to produce good broccoli seed
yield of good quality. As substantial differences in nutrient solution composition did not
significantly affect the quality of broccoli seed produced. Seed yield was however significantly
affected by nutrient solution composition.
Key words: Brassica seed, broccoli seed, seed production, broccoli nutrition, hydroponic
production, broccoli production, nutrient assimilation. / AFRIKAANSE OPSOMMING: Min inligting is bekend rakende die voedingsbehoeftes van brokkoli wat gekweek word vir
saadproduksie. Gedurende 2006 en 2007 is brokkoli gekweek vir saadproduksie in sakke sand in
‘n net struktuur met ‘n oop hidroponiese besproeiingstelsel. Die proefontwerp was ‘n ewekanisige
geheel blok met sewe behandelings wat ewekansig binne bloke toegeken is en herhaal is in vier
blokke. Sewe voedingsmengsel behandelings is gedurende 2006 toegepas. Die Standaard
mengsel is geskoei op Steiner se universele mengsel en dit is vergelyk met verskillende vlakke
van N, S, K en Ca t.o.v. die invloed daarvan op biomassa produksie, voedingselement
konsentrasie, voedingselement assimilasie, saad opbrengs en saad kwaliteit. Biomassa
geproduseer het nie wesenlik verskil nie. Totale droë massa het met 225% toegeneem vanaf die
volwasse kop tot die oes stadium. Die konsentrasie van voedings elemente in plant monsters is
nie beïnvloed deur behandelings nie behalwe in gevalle waar lae konsentrasies van K en S in die
voedingsmengsels gelei het tot lae konsentrasies van K en S in plantontledings. Die totale
opname van voedingselemente is bereken om die effek van die veel langer groeiperiode wat
benodig word vir saadproduksie in vergelyking met normale kop produksie te bepaal t.o.v.
voedingselement behoefte. Makro element opname per hektaar was as volg: N 173.0 kg, P 35.5
kg, K 348.4 kg, Ca 114.7 kg, Mg 30.5 kg, S 42.2 kg.
Die sewe behandelings van 2007 het drie behandelings van 2006 ingesluit asook behandelings
van blaarbespuitings met Ammonium Nitraat en Kalsium Metalosaat. Die Standaard
voedingsmengsel is weer gebruik ten einde die resultate van 2006 en 2007 te vergelyk.
Voedingselement ontledings op plante van die Standaard mengsel (2006 & 2007) is vergelyk en
het soortgelyke tendense aangedui. Soos wat plante ontwikkel het na volwassenheid was daar ‘n
relatiewe toename in konsentrasie in die boonste plant dele (peule, blomme en stele) van Ca, Mg
en S. In teenstelling hiermee het die konsentrasies van N en P afgeneem. Die mikro elemente
Fe, Mn en B het ook in konsentrasie toegeneem in die boonste plant dele teen oes wat daarop
dui dat daar ‘n sterk relatiewe vloei van hiedie elemente na die boonste plant dele plaasvind met
volwasse wording. Die konsentrasie vlakke van makro elemente in plantontledings het in die
algemeen wesenlik verskil tussen die twee jare. Die voedingselement konsentrasies was in die
algemeen hoër in die saad peule as in die res van die plant wat daarop dui dat die peule as ‘n
sterk sink op die plant funksioneer.
In beide jare was die hoogste opbrengs afkomstig van die Standaard voedingsmengsel en die
Standaard – K mengsel wat lae vlakke van K bevat het. Gedurende 2006 is geen wesenlike
verskille in saadkwaliteitsnorme gevind nie. Soortgelyke resultate is gevind in 2007 behalwe vir
grootte van die kiemblare. Die resultate dui daarop dat dit nie nodig is om die Standaard
voedingsmengsel samestelling te verander ten einde goeie opbrengs saad van goeie gehalte te
produseer nie. Wesenlike verskille in voedingsmengsels het geen invloed op die kwaliteit van
brokkoli saad gehad nie. Saad opbrengs is egter wesenlik beïnvloed deur die samestelling van
die voedingsmengsels.
Sleutel woorde: brassica saad, brokkoli saad, saad produksie, brokkoli voeding, hidroponiese
produksie, brokkoli produksie, voedingstof assimilasie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/6642 |
| Date | 03 1900 |
| Creators | Du Randt, Marius Louis |
| Contributors | Langenhoven, P., Agenbag, G. A., University of Stellenbosch. Faculty of AgriSciences. Dept. of Agronomy. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 143 p. : ill. |
| Rights | University of Stellenbosch |
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