AGRONOMIJAS VĒSTIS - Latvijas Lauksaimniecības universitāte

AGRONOMIJAS VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008ripeness for the treatments harvested by different methods (Table 1). When fodder galega podswere green, the seed harvested by different methods were still underdeveloped, 1000 seed weightamounted to 4.11-5.31g. Seed germination was low 52-72% and did not meet the standard. In moremature yellow or semibrown pods the seed had reached the weight maximum and the germinationstill had a tendency to increase. The quality of the seed of this pod maturity group was similar tothe quality of fully ripe seed. Consequently, harvesting time of fodder galega seed crop can bedetermined according to the content of yellow and brown pods in the crop.Table 1 Fodder galega seed quality of different maturation and harvested by different methods(mean of 1996-1999)HarvestingmethodGreen pods, greenseedYellowing-greenpods, green seedYellow pods, lightyellow seedBrown pods,yellow seed1000seedweight, ggermination,%1000seedweight,germination,%1000seedweight,germination,%1000seedweight,germination,%gggSwath 4.11 62 6.32 81 7.19 87 6.70 90Direct after 4.24 52 6.02 81 6.89 82 6.88 92defoliationDirect without 5.31 72 7.10 88 6.95 82 6.69 89defoliationLSD 0.05 1.01 29 0.54 5 0.54 8 0.46 6Fodder galega seed yield is generally higher than that of other legumes and depends on the age ofthe crop and the weather conditions (Vavilov and Kondratjev, 1975; Raig, 1994). During ourexperimental period the highest rate of precipitation fell in 1998. The driest growing seasonoccurred in 1999. The lowest seed yield was produced by fodder galega in the first year of use(Table 2). Due to the drought and frosts in May the seed yield in the fourth year of use declinedmore than twice compared with the seed yield in the second and third year of use. Averaged datafrom four years indicate that the highest seed yield 521 kg ha-1 was obtained when fodder galegawas direct-harvested after 90% of pods had ripened. Comparison of swath harvesting and directharvesting involving defoliation shows that for two years significantly higher seed yield wasobtained in the direct harvesting treatment, in the other two years the seed yield was similar forboth harvesting methods. When the seed was harvested without defoliation the seed yields obtainedwere significantly lower. Only in very dry year 1999 the seed yields were similar for both directharvesting with prior application of the defoliant reglon and for seed harvesting without defoliation.Most researchers consider direct harvesting method as the main and recommend harvesting foddergalega after 70-80% pods had matured (Vavilov and Kondratjev, 1975; Spruogis,1999). Earlyharvesting of fodder galega when 60% of pods had ripened was not justified. Lower seed yieldswere obtained in all years of use. A two-week delay in harvesting resulted in a seed yield reduction,however, this decline was significant not every year.Table 2. Fodder galega seed yield, harvested by different methods and at different timesMethod of MaturedSeed yield, kg ha -1harvesting pods, % 1996 1997 1998 1999 AverageSwath 60±5 107 532 493 184 329Swath 80±5 144 643 703 239 432Direct 80±5 187 639 748 272 462Swath 90±5 192 737 728 282 485Direct 90±5 235 758 775 315 521Direct× 90±5 183 662 685 316 462Swatha 177 650 714 272 453Direct a 202 655 709 315 470Directa× 168 603 673 332 444LSD 0.05 14 56 80 33 26a - harvesting 14 days after last term× - direct harvesting without defoliation172