No abstract

The effect of three harvest intervals (30, 45 and 60 days) on the yield, crude protein (CP), digestible protein (DP), and mineral (calcium, Ca; phosphorus, P; potassium, K; and magnesium, Mg) composition of 10 forage grasses was determined during a 1-year period at the Isabela Substation. The species studied included three Brachiarias, five Digitarias and two Cynodons. As the 30-day harvest interval, the dry matter yield (DMY) ranged from 25,859 to 19,041 pounds per acre per year. The highest DMY was obtained by Transvala digitgrass (Digitaria decumbens, PRPI. 6439) Stargrass (Cynodon nlemfuensis PRPI. 2341) had the highest CP and DP contents. The highest DMY at the 45-day interval was obtained by Transvala digitgrass, being significantly different (P < .05) from other grasses. The DMY ranged from 29,532 to 20,962 pounds per acre per year. Digitaria eriantha had the highest CP and DP contents. Stargrass had the highest DMY and CP at the 60-day harvest interval. The DMY ranged from 37,504 to 30,269 pounds per acre per year. Mean Ca and Mg contents in the grasses increased at the 45-day interval, with no Ca increase but a Mg decrease at 60 days. Mean P and K contents decreased as the harvest intervals increased. The yielding ability of the grasses was encouraging, especially in the Transvala digitgrass and Stargrass species. The CP and DP contents tended to vary as plants matured, suggesting that studies of mineral absorption and/or utilization of forage grasses by niminants should be undertaken.

The effect of different levels of N, P, and K with and without Ca, Mg and two levels of calcium silicate, was studied on Kaki pigeonpea in an Oxisol at the Isabela Experiment Substation. The study confirmed previous results showing that fertilizer treatments have no effect on green pod yield, date of flowering, plant height, seed weight or protein content of the dry seed.

Pigeon pea (Cajanus cajan cv. 38-Bushy) seeds were harvested at maturity and 1, 2 or 3 weeks after maturity (delayed harvests) from non sprayed plants or from plants sprayed with maneb, benomyl, or a combination of the two at four 1-week intervals beginning 110 days after planting. At each harvest date, the decrease in percentage germination and emergence and the increase in seed borne fungi was significantly less for seeds from benomyl-sprayed plants than from nonsprayed plants or those sprayed with maneb. The percentage seed germination in vitro and field emergence decreased and the percentage of internally seedborne fungi increased with each delay in harvest for all treatments. There were no significant differences in total internally seed borne fungi, germination in vitro, or field emergence between plants sprayed with maneb alone and the nontreated control. When harvested at maturity, plants of all treatments produced good quality seeds (over 85% germination).

Pigeonpea cultivar Kaki was grown during 1970-71 to determine the effect of planting date, plant population and row spacing on green-pod yield, date of flowering, plant height, protein content of the seed and yield components. Green-pod yields were significantly higher in plantings made during early April, May and June than during late September and October. Yield also tended to be higher at lower spacing between rows, and at highest populations, regardless of row spacing. Plant height, number of days to flower and protein percent of the dry seed were unaffected by row spacing and plant population, but these factors were affected significantly by date of planting. Pods per plant increased markedly as spacing was increased and with early plantings. Date of planting, row spacing and plant population had no affect on seed size or number of seeds per pod.