Abstract
In order to see the mechanisms of pod break down in peanut, the strength requisite for detaching the pod from the gynophore was examined, firstly. In this experiment, the pod break down occured by the breaking at the junction of gynophore and pod, or gynophore itself. The strength was measured with unbonded gauge type transducer (LT 51kg) and automatic null balancing recorder (fig. 1). Varieties were Java No. 13, Kikuyo and Chiba-handachi. Materials were taken at 5, 10, 20, 30, 40, 50, 70, 90, 110 and 130 days after flower open. Each experimental lot consisted of about 15 pods. Results were as follows. 1. The strength requisite for detaching the pod from gynophore increased with the number of days after flower open. At 30 days in Java No. 13, 40 days in Chiba-handachi and 50 days in Kikuyo after flower open, the strength was maximum. It was about 1.6kg in Java No. 13 and Chiba-handachi, and about 1.3kg in Kikuyo, respectively. Thereafter, the strength decreased with the number of days in gradually. At 50 days in Java No. 13 and at 70 days in Kikuyo after flower open, the strength was 1.1 kg in the former and 0.7 kg in the latter. In these two varieties, the strength was almost the same from this time to harvest time. In Chiba-handachi, on the other hand, the strength decreased from the time of maximum strength to harvest time. 2. At the time of maximum strength, seed size (weight of seed dry matter) were about 1/4 in Chiba-handachi, about 1/3 in Java No. 13 and about 2/3 in Kikuyo as compared with that at harvest time. In these three varieties, effect of seeding time on the strength was not obvious. Maximum strength at the duration from 50 days after flower open to harvest time was about 1.1∼1.3 kg in Java No. 13, about 1.2 kg in Kikuyo and 1.2∼1.4 kg in Chiba-handachi. On the other hand, the strength at harvest time (about 110 days after flower open) were about 1.1∼1.3 kg in Java No. 13, about 0.8 kg in Kikuyo and about 0.7 kg in Chiba-handachi, respectively.
