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The study was carried out during 2014 and 2016 to identify the effect of climate change on field and energy renewable crops production in the farmer level in major cropping areas of each crop. The experiments were assigned in 3 project activities. The objectives in the first activity were focused on the change in farmer’s production technology, insect pest, plant disease occurrence, weed incidence, yield quality, risk analysis in crop production and Life Cycle Assessment (LCA) of major economic field crops. Economic crops studied were composed of mungbean, soybean, field corn, sweet corn and sesame. The tools for the study were surveying, interviewing with questionaire, sampling and climatic data collection both primary and secondary. The results showed that the change in climate concerning crop productivity was realized in case of higher maximum and minimum temperatures than normal (30 based year average: 1971-2000), both lower and higher annual rainfall, less number of annual rainy days causing heavier rain each time, finally, waterlogging and lower yield. Rainfall pattern have varied to unexpectable amount and start in the dry, early rainy and late rainy seasons, frequent dry spells during rainy season. Farmer’s adaptation in production technology already happened such as shifting planting date until there was rain in sesame, sowing mungbean before harvesting corn in relay cropping to use soil moisture left, soil preparation before growing mungbean, more frequent chemical insecticide spraying. It was found that aphids and thrips always appeared in several crops grown in drought condition such as in soybean (Mae Hong Son), sesame, sweet corn and drought often occurred many times in a year. Leaf roller was not an important key pest for soybean but it occurred in every year including white fly which is a key one. In maize, climatic change promoted several diseases: Curvularia leaf spot, maize dwarf mosaic, brown spot, banded leaf and sheath blight, southern corn leaf blight, southern rust, downy mildew, charcoal stalk rot, bacterial stalk rot, Penicillium and Fusarium ear rot and smut. Disease severity ranged from low to moderate depending on weather conditions within locations. Leaf spot, brown spot and banded leaf and sheath blight were found to be more severe in heavy rainfall or continuous rain. Curvularia leaf spot attacked sesame for the first time in Mae Hong Son. Weed occurrence did not show major relationship with climatic change but was well known to be important constraint for cropping in the Tropic which needed to control. Possible relationship could be the more growth of C4 weed in the higher concentration of CO2 than C3 weed and shift of some weeds’ habitat to higher topography. These results provided useful data for adaptation to climate change condition and need more and longer studies. In the second activity, the objective was to study the response of field crops and improve crop production to adapt to climate change. The experiments were carried out in the Research Centers on sweet corn (Chai Nat Field Crops Research Center), cassava (Rayong Field Crops Research Center), and sesame (Ubon Ratchathani Field Crops Research Center). They consisted of 6 experiments: 3 planting date studies, 2 drought condition response studies (sweet corn and sesame) and cassava disease incidence in a year. The first one was planting date study in the dry season of sweet corn (2014-2015), RCB with 4 replications of 10 treatments, planting from November 15 – April 1 at 15 - day interval. It was showed that mid-November planting to beginning of February was optimum planting date range for sweet corn as it provided highest fresh ear yield (with husk) of 2,798-3,673 and 1,843-3,234 kg/rai and planting from mid-February was not recommended because of low yield. The second experiment was the response of sweet corn to drought and N and P fertilization in 2014-2015. Split plot design was applied with 3 replications. Main plot was surface ground water level of 2 levels, (1) sufficient water for sweet corn growing season (control) and (2) induced drought condition (by stop watering at 14, 28 and 34 days after emergence (DAE) and water sufficiently again after 35 DAE. Subplot was N and P fertilization practices in the recovery stage or at 37 DAE of 4 levels i.e. (1) no N and P fertilizers (2) 15 kg/rai of N fertilizer (3) 15 kg/rai of P2O5 fertilizer (4) 15 - 15 kg/rai of N and P2O5 fertilizer. Sweet corn was sown in November and harvested in February. It was concluded that after sweet corn was in drought during 14-35 DAE, fertilization with 15 kg/rai of N fertilizer or 15 - 15 kg/rai of N and P2O5 fertilizers was recommended at the recovery stage (37 DAE) as this provided worthy high yield (2,654-3,319 kg/rai of fresh ear with husk). The third experiment was cassava diseases evaluation in the field which was conducted in 2014-2016. It was done without experimental design but by growing 4 cassava varieties, Rayong 5, Rayong 9, Rayong 11 and Kasetsart 50, in large plots and evaluated disease incidence randomly every month until harvesting. The cassava diseases interested were cassava bacterial blight, cassava brown leaf spot and anthracnose. It was revealed that bacterial blight and brown leaf spot attacked cassava in 2014 more than in 2015 and 2016. The reason was more rainfall amount in 2014 (1,381.6 mm) than in 2015 (1,228.5 mm) and 2016 (1,119.8 mm) causing higher humidity in the cassava canopy. The more mature cassava was, the more leaf blight attacked. Leaf blight was found in July to August most and Rayong 5 variety was more susceptible than the others. Brown leaf spot occurred in October onwards and Rayong 5 and Kasetsart 50 were more susceptible than the others. Anthracnose was not found in the experiments. The fourth and fifth experiments were planting date in the dry and rainy seasons of sesame for grain and seed in 2014-2015. RCB with 3 replications was applied and red seeded Ubon Ratchathani 84-4 sesame variety was studied. There were 10 treatments of planting date from mid-November to end of March, 15-day interval for the dry season and from mid-April to end of August for the rainy season. It was found that mid-February to mid-March planting was suitable for sesame in the dry season according to higher yield, 61.7-103.0 kg/rai, in 2014 but end of March planting was good in 2015 (yielded 94.0 kg/rai). In the rainy season, mid-April to beginning of May (64.3-68.7 kg/rai) and beginning of September (54.0 kg/rai) plantings gave higher sesame yield in 2014 and 2015. For sesame seed production, planting on the end of January to mid-February was optimal in the dry season as providing higher yield and seed germination (36-54 kg/rai and 85-94% of germination). The beginning of September planting was optimal for sesame seed production in the rainy season (low yield of 10-30 kg/rai but 89-91% of germination). The sixth experiment was to study sesame growth and yield response in drought condition by applying RCB with 4 replications and 9 treatments of the start of drought by stop watering in the dry season at 14, 21, 28, 35, 42, 49, 56, 63 and 70 DAE. It was concluded that drought happened from 14-35 DAE caused slow growth, stunt and low yielding. The third activity was to study the effect of kaolin-clay in producing cassava and reduce chemical pesticide application, four experiments were conducted in 3 sites, Rayong Field Crops Research Center, Sukhothai Agricultural Research and Development Center and Phitsanulok Seed Research and Development Center in 2014-2016. RCB was applied to the experiment with 4 replications and 7 treatments of spraying substances, consisting of 1) not spray anything 2) spray water 3) spray insecticide thiamethoxam (4 g/ 20 l) 4-7) spray kaolin-clay at the rate of 20 40 60 and 80 g/ 20 l of water. Cassava varieties studied were Rayong 5 and Rayong 9, plant spacing was 1x1 m. Plot size was 8x5 m and 15-7-18 of N-P2O5-K2O for 50 kg/rai was applied to each treatment at 1 month age. The spraying was done every month for 6 months. Data collected were leaf surface temperature and plant height each month until harvest for the first experiment, yield and starch percentage for the second one, insect pests occurrence for the third one and cassava diseases incidence for the fourth one. Climatic data in the experimental sites were also collected. It was concluded that all rates of kaolin spraying did not affect leaf surface temperature as it varied in between maximum and minimum temperatures in every treatment. Plant height was not significantly different for all type of sprayings. For yield and yield quality, kaolin did not cause any statistical difference in cassava yield, % starch and harvest index (HI). Cassava yield was lied between 1.5-16.2 kg/rai for Rayong 5 and 5.8-15.7 kg/rai for Rayong 9 in all sprayings and spray nothing treatment from 3 sites. Starch percentage was 20.4-28.1% in Rayong 5 and 26.7-30.1% in Rayong 9. Finally harvest index was 0.42-0.65 in Rayong 5 and 0.53-0.66 in Rayong 9. For insect pest control, mealy bug, red mite and whitefly were not significantly different for all treatments, so kaolin did not affect in decreasing insect pest. Red mite and mealy bug increased when drought or dry spells happened such as in April to May or December to April whereas whitefly increased in both drought and a little rainy condition. For disease control, cassava bacterial leaf blight and brown leaf spot were not significantly different because of type of spraying therefore kaolin did not have the effect in controlling disease. Both diseases occurred after raining when there was humidity under the leaf canopy. In other word, spraying kaolin, chemical pesticide (thiamethoxam) and spraying water can be used in cassava production giving no difference in yield and pest control. Better choice of technology will be made easily if cost and income analysis has been done. Further studies should be focused on using kaolin to help in drought tolerance. |
