Effects of Macronutrients and Cutting on Mulberry Cultivars in Malaysian Peat

Abstract

N, P and K fertilizers improved mulberry leaf, stem and fruit yields on peat, the optimum rates being ioo kg/ha/yr N, 25 kg P and 62-5 kg K, with further leaf responses to N and K if applied together in the ratio of 3:2. Harvesting every 2 months at 60 cm height gave better yearly leaf yields than cuttings 3-12 months apart, but annual stem yields were not affected by harvesting frequency and fruit yields were optimum when plants were cut at intervals of 5-6 months. Harvesting quarterly at 60 cm produced better leaf and stem yields than cutting lower (15 and 30 cm) or higher (100 and 180 cm). Two Thai cvs (Noi I and Mii) were female-sterile but the Local Malaysian producer! fruits.The Malaysian Government has shown interest since 1972 in silkworm culture as a potential cottage industry, which is now increasingly important in some states, e.g. Trengganu (Nik Yusoff, 1974). However, the success of sericulture depends on the production of adequate amounts of mulberry {Moms alba) leaves on which the growing silkworms feed, but little research has been done on mulberry production in Malaysia although it grows as a wild wayside shrub. Since information on the productivity of mulberry in relation to different agronomic and fertilizer regimes is urgently needed, the experiments reported here were conducted on peat at Jalan Kebun, where the crop was experimentally established in 1972 for observation and work on propagation by stem cuttings, though without culturing silkworms at the station. EXPERIMENTALFour field experiments, conducted during 1975-77, studied the effects of macronutrient fertilization, harvesting frequency, height of cutting and different cultivars on the productivity of mulberry, by cutting the stems at regular frequencies and not by the usual method of cutting and/or leaf plucking according to the needs of the silkworms that are being fed (Anon., 1973). The treatments were:Experiment I-o, ioo and 200 kg/ha N as urea; 0, 25 and 50 kg/ha P as superphosphate; ando, 62-5 and 125 kg/ha K as potassium sulphate, with all levels factorially combined. Experiment 2-Harvesting at frequencies of 2, 3, 4, 5, 6, 8, 10 and 12 months, Experiment 3-Harvesting at heights of 15, 30, 60, 100 and 180 cm, and

Liming Needs of Sweet Potato in Malaysian Acid Peat

“…We also observed a close seasonal relation between tuber yield and the degree of infestation with tuber weevil (Cylas formicarius). However, successive yield reductions may also have been partly due to progressive depletion of non-nitrogenous plant nutrients, since minimal P and K were applied throughout these experiments and increased availability of N with liming would then require additional K in order to maintain the N:K ratio needed to prevent reduced response to N (Chew et al, 1980a).…”