Performance of rice (Oryza varieties under different sativa) times of planting
Keywords:
Rice, YieldAbstract
A field experiment was conducted during the rainy (kharif) season of 1997 and 1998 on alfisols at Agricultural Research Station, Utukur, Cuddapah, Andhra Pradesh, to study the performance of 4 varieties of rice (Oryza sativa L.) under different times of planting. Planting of rice varieties on 16 August gave significantly higher grain yield than that of other times of planting. Among rice varieties, NLR 33641 outyielded other varieties. Irrespective of rice varieties, the grain yield decreased by 175 and 170 kglha for every 15 days delay in planting during 1997 and 1998 respectively.References
Performance of rice (Oryzasativa)varieties under different times of planting
C. SlJBBl REEDY
Agricultural Research Station, Acharya N.G. Ranga Agricultural University, Utukur, Cuddapah 516 003 (Andhra Pradesh)
Received :September 2001
A field experiment was conducted during the rainy (kharif) season of 1997 and 1998 on alfisols at Agricultural Research Station, Utukur, Cuddapah, Andhra Pradesh, to study the performance of 4 varieties of rice (Oryza sativa L.) under different times of planting. Planting of rice varieties on 16 August gave significantly higher grain yield than that of other times of planting. Among rice varieties, 'NLR 33641' outyielded other varieties. Irrespective of rice varieties, the grain yield decreased by 175 and 170 kglha for every 15 days delay in planting during 1997 and 1998 respectively.
Key words :Rice, Yield
Under natural conditions, environmental MATERIALS AND METHODS factors are the most difficult to be
The field study was conducted at controlled and exert a profound effect on
Agricultural Research Station, Utukur, crop growth and grain yield of rice.
Cuddapah (Dist.) during the rainy (kharif) Therefore, a considerable v+ation in plant
season of 1997 and 1998. The experiment behaviour for its vertical and horizontal
.#. comprised 4 dates of transplanting (16 extension in the field is natural. Growth
August, 1 and 16 September and 1 October) parameters could serve as an index for
in main plots and 4 rice varieties ['BPT rapid selection for higher photosynthetic
' and '1vlTU 4870' (medium duration efficiency and productivity, particularly for
of 140-145 days) and 'NLR 28600' and new high-yielding rice varieties of mid-and
'NLR 33641' (long duration of 150-160 late-maturing group. Hence, the present
days)] in subplots. The soil was red sandy study was taken up to identify suitable rice
loam, having pH 8.1, electrical conductivity varieties and the suitable time of planting
16 mmhos/cm, organic carbon low .-for rainy (kharif) season. (0.45%) and 19.0 and 490.0 kglha available
SUBBI REDDY [Vol. 47, No. 2
P205 and $0 respectively, where the plant height and test weight were
The crop was planted at a spacing of 15 higher on 1 September 1997 transplanting cm x 15 cm with 2 seedlingshill in split- (Table 1). In 1997, the differences in these plot design keeping 4 replications. parameters between 16 September and 1 Staggered sowing of nursery was done 1 October were not significant except produc- month before transplanting to get 30-day- tive tillers/m2, wheieas in 1998 the 16 old seedlings at the time of transplanting. August planting was either significant or at The crop was fertilized with 100 kg N, 60 par with 1 September transplanting. Among
kg P20,, 40 kg K20/ha. Nitrogen was varieties, 'NLR 28600' gave significantly applied in 3 equal splits at transplanting, taller plants than other varieties during active tillering and panicle-initiation stage. 1997, whereas in 1998, 'NLR 33641' Full dose of P205 and $0 were broadcast produced significantly taller plants com- uniformly at the time of transplanting. pared with other varieties. The variety 'BPT 5204' recorded lowest values of ail
RESULTS AND DISCUSSION
yield attributes.
Yield attributes
Plant height, productive tillers/m2, filled Yield and harvest index grainsJpanicle, and test weight were found The highest grain and straw yields were highest in the crop transplanted on 16 recorded in 16 August transplanting and August, followed by 1 and 16 September, were significantly superior to other dates of and lowest in 1 October planting, except transplanting (Table 2). There was 7, 15
Table 1. Effect of time of transplanting and rice varieties on yield attributes
Treatment Plant height Productive Filled grains1 Test weight (cm) tillerslm2 panicle (g)
1998 1997 1998 1997 1998 1997 1998
Time of transplanting (TT)
August 1 kg. 1
September 121.8
September 118.4
October 116.8
CD (P=0.05) 2.5 Varieties (V)
'BPT 5204' 87.3
'MTU 4870' 101.5
'NLR 28600' 146.6
'NLR 33641' 140.9
CD(P=0.05) 3.8 Interaction
NS, Not significant
June 20021 RICE RESPONSE TO PLANTING TIME 201
Table 2. Effect of time of planting and rice varieties on yield and harvest index
Treatment Grain yield (kglha) Straw yield (kglha) Harvest index
1998 1997 1998 1997 1998
Time of transplanting (TT)
August 4,669 4,687 :
September 4,372 4,287
September 4,061 3,870
October 3,604 3,696 CD (P=0.05) 253 237 ,
Varieties (V)
'BPT 5204' 3,366 3,461
'MTU 4870' 4,167 4,113
'NLR 28600' 4,497 4,357
'NLR 33641' 4,676 4,574
CD(P=0.05) 232 203 Interaction
NS, Not significant
