Recently developed early, short -statured Pima strains may be adapted to 30-inch row culture.

Fruit load affected plant heights of normally tall and short Pima cotton genotypes differently.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / Starch levels in stem and root bark of cotton plants decreased when boll loads increased.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / In the 1985 Pima Regional Tests, no strain yielded significantly above Pima S-6 at individual test sites. An official release was made for okra-leaf shape, frego bract shape, glandless plant and seed, nectariless, and male-fertility restoration noncommercial germplasm lines of Pima cotton. These germplasm lines incorporating genetic traits with potential economic value may be especially useful in developing parental material for hybrid cotton.

Five experimental strains and Pima S-6 were grown in nine Regional Tests across the Pima belt in 1987. Experimental strain P70 averaged highest in yield both below and above 2,500 foot elevation. The difference in yield between Pima S-6 and P70 across all locations was 48 pounds of lint per acre. Sequential harvests at Phoenix and Safford, AZ, indicated that P70 was the earliest and Pima S-6 the latest entry in the 1987 Regional Test.

Seed increase of 104 accessions and data collection on 65 accessions were obtained in 1988 to further the maintenance and evaluation of the Gossypium barbadense L. germplasm collection. In a program of conversion of tropical non flowering cottons to a day-neutral flowering habit, 63 accessions were advanced 1 generation by backcross. A systematic screening of the G. barbadense collection for bacterial blight resistance involving 200 accessions from 21 countries yielded 8 accessions resistant to races 1, 2, 7, and 18 of the pathogen. Genetic inheritance and linkage investigations of a male sterile and a foliar mutant progressed. An investigation of the geographic and taxonomic distribution of the ovate leaf trait was concluded with negative results. The frequency of the 2 mutant genes ov₁ and ov₂ proved to be too rare to yield meaningful taxonomic or geographic information about the species. Preliminary results from a performance evaluation of interspecific hybrid cottons conducted at Maricopa and Safford AZ, indicated strong environmental influences on hybrids, but generally favorable yield earliness and plant height data were obtained from the higher -elevation Safford location.

No description available.

No description available.

No description available.

The relationship between lithology and slope morphology is investigated at eight sites on granitic, andesitic, and sedimentary rock slopes in the Tucson Mountains. Several methods are used in the study. Topographic profiles are constructed. Skewness indices of the slope shapes, maximum and minimum slope angles, and slope lengths of the different slope profiles are computed and compared with each other. Debris size analysis is done to better determine hillfront/piedmont junctions. Slope surface regularities of the three lithological slopes are analysed and compared. The results show that the granitic piedmont slopes are found to be slightly concave to almost rectilinear, indicating their high resistance to erosive processes. In contrast, the concavity of the andesitic and sedimentary piedmont slopes demonstrate their inability to resist the erosive attack on them. However, in the case of the hillfront slopes, slope forms do not reflect lithological variations.