Peanuts: the quality of mechanically damaged seeds and a comparison of seeds of different origin

Production of peanut seeds is complicated, as they are sensitive to mechanical damage, which results in distorted, cracked and broken seeds. Cracking of seed coats and cotyledons have caused low germination, retardation in the growth of seedlings, and the penetration of micro-organisms into embryos. In view of recent changes in agricultural technology, the link between cracked seeds and seed quality was studied. Peanut seeds cv. 'Shulamit', the most popular in Israel, were manually examined and sorted as cracked seeds (fissured coats and unstable cotyledons) and undamaged seeds. Both categories, as well as unsorted seeds, were sown in the field. Germination ability of cracked seeds was found to be no different from that of undamaged ones. Furthermore, there was no difference in germination rate and percentage, in yield, and in pod classification by size (Giant, Extra Fancy). In view of the results obtained, further tests will be conducted in a semi-commercial experiment to verify these data. In another experiment, seed samples were drawn at pre-treatment and sowing stages. We know that treatment, packing, handling, transportation, and the sowing itself, influence seed viability and cause higher cracking levels. We cannot yet determine, however, when the damage occurs. To examine the effect of seed origin on seed viability, six seed lots of cv. 'Shulamit' were sown in the Nir-Yitzhak farm. Germinability of seeds treated with Marpan + PCNB (powder) was found to be higher than that of those treated with Busan (mist). Busan possibly slowed down germination. Yield of pods was statistically the same in all the lots (624-675 kg/1000 m2), as was the percentage of Extra-Fancy pods obtained (70-76). However, the percentage of Giant pods was significantly higher in seeds from Kerem Shalom and Magen farm (9.5 and 8.8 respectively), as compared to seeds from Gvulot (4.8). In these experiments it was again observed that much higher germinability was obtained in the laboratory (86-94) than in the field (46-71). This result is similar to observations made over the last few years. Hence, it is essential to develop laboratory methods that will predict field performance at a much higher level of correlation