タイトル |
苗水分ストレス指数を用いた「コシヒカリ」の健苗育成指標 |
担当機関 |
福井県農業試験場 |
研究期間 |
1999~1999 |
研究担当者 |
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発行年度 |
1999 |
要約 |
放射温度測定により求めた潅水前の水稲苗の表面温度などから算出される苗水分ストレス指数(SWSI)により、移植時の苗質(苗丈,茎葉重)が推定できる。健苗育成のための苗水分ストレス指数の平均値は、0.3前後である。
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背景・ねらい |
水稲苗の表面温度などから求めた苗水分ストレス指数は、苗の水分状態の指標として活用できることが明らかにされている(北陸農業研究成果情報第14号:19-20)。そこで、育苗期間中の灌水管理の指標化のために、継続して測定した苗水分ストレス指数と苗質の関係を明らかにし、健苗育成に活用する。
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成果の内容・特徴 |
- 平均気温が異なる育苗試験の結果より、湛水管理した苗の苗丈は平均気温が高くなるほど伸長するが、灌水量を控えることにより特に高温条件で苗丈の伸長を抑えることができる(図1)。
- 苗水分ストレス指数(Seedling Water Stress Index:SWSI)は、午前、午後の潅水前に測定した苗表面温度などより算出し(表1の凡例)、苗1葉期以降毎日平均する。苗の萎凋開始時のSWSI値はおおむね0.3~0.4であるが、気温15℃以下の低温多湿条件では萎凋程度診断への適用性は不十分である。したがって、育苗期間平均気温が15℃以上の育苗条件で適用性が高い(図2)。
- SWSI値の育苗期間(苗1葉から2.0~2.5葉期)平均値と移植時苗丈の間には負の相関関係が認められる(図3)。また、SWSI値が0.35を上回ると、移植時の茎葉乾物重が低下する傾向が認められる(図4)。したがって、SWSI値を継続測定することで移植時の苗質が推定でき、灌水量診断に活用できる。
- 健苗としての稚苗の苗丈の指標は10~15cm、茎葉乾物重の指標は10~12mg/本であるため、育苗期間の潅水前平均SWSI値は 0.3前後が適している。この値は苗の萎凋直前の値に近い。SWSI値を判断材料として育苗途中で灌水量を変更することにより、苗質を健苗に近づけることができる(表1)。
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成果の活用面・留意点 |
- SWSI値は、簡易なスポットタイプ放射温度計を用いても算出できるため、現地においても適用が可能である。
- 本試験は、「コシヒカリ」を用いて箱あたり播種量120g、床土窒素量1.5gで実施している。このため、品種や播種量、施肥量が異なると推定値も異なる点に留意する。
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図表1 |
![214372-1.gif](https://s3-agre-content.s3.ap-northeast-1.amazonaws.com/assets/images/seika_chart/214372-1.gif?X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDmFwLW5vcnRoZWFzdC0xIkcwRQIhAOy5T26HbvG3Qzv6ZzSfQ2QDOKXziQ9CiSqF%2BxoLby79AiApIgn7rpdxe51pnKHNLbT1RdlFS03IbEyK%2F0jThFksqCqZBAiE%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDUzMjMzMTA3MjA0MSIMgyRhHSUjzOS%2BIvmEKu0DeeFYWUquMF04dZEmYlvlth7Yxa1KCSShdpBBtkQbCHasG3VCzOXhUsxRYwg%2BDFoSJGyo1UhluIBv1HjH6nexn7rYFNicvZ1%2Bukg1wjfmbiD%2BeFaYSmh19rw6f3IYk%2BecyVXkxBUTSuyO27jcfM3jaIUqdwcJHD60B9vFZ4j3jTLE4H1n6eCKSfZt7V23gMr6agzujSmEZC%2F7jchd8d3J%2Br360QC0UvZ4hosIaDmSGJmiUTKfrAaeOeie78IClIhYPrmOy8oI3fzFyhKekz8uNUqq74eaZvw%2F3vw%2Fv4SiPyU0cZmFv0%2BdGDPoqUGgxxWSfRi6he%2FmoGzXxbhFfeBmbFKpq8OgDILV8CTbFZfuxr9FVoxBl0E2%2FOmDmYOlW5Hn1f5R%2BCx7AY%2F2lrL0A%2FNkIlTODh9bCXWRcrzqkqc3vYh7FHk4g%2Bj5rrYkdFiBX836FSVaDFlxiIqPL4XQkKCtBgK%2BVJrKsQDXcc4dPQkv8B9yUXC2HpFz3LH1RuihfjA46aBWWNkf8AuCH%2BenGOMkKlAkiSDSinh49vb4yDNHGJNpfIH%2FjieEfY%2BtiAcn0E5glSxzaW%2BMvM6Ct3gtphhg1W5S1ICRsDzpHUExmkW4qDc8TlA3DO%2BEj0KsfkpnAdYsQeshY6BbqkDJfZD5NjChpN6zBjqmAbhaFHsiS7tBtLL7xVmK7WcaE4KN9Lon%2BZPVuNmDf7%2B4Or%2B7S5NyTx6wXhCAYILzaXQdzZMPNXyX54LAbxXoxosOyZfS7VIT4uUAJ28uLIdHGKV4pXrR9ZJvCsOiWDb0NORdgoWmqPQJ9snwOCpkaNrhhDDz382sOhQugKPxYUM98mHjxDwcDNH1n8bXSCCdEIqLbenwxYjObkvM3uTvc1nPPxHe9kM%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAXX4LHRIUUJXW7X6P%2F20240623%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20240623T032933Z&X-Amz-SignedHeaders=host&X-Amz-Expires=1800&X-Amz-Signature=2a8b605b6b5e8c3827ceae3dbe43612c04ef9786cec17e83d1b91fecb968500e) |
図表2 |
![214372-2.gif](https://s3-agre-content.s3.ap-northeast-1.amazonaws.com/assets/images/seika_chart/214372-2.gif?X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDmFwLW5vcnRoZWFzdC0xIkcwRQIhAOy5T26HbvG3Qzv6ZzSfQ2QDOKXziQ9CiSqF%2BxoLby79AiApIgn7rpdxe51pnKHNLbT1RdlFS03IbEyK%2F0jThFksqCqZBAiE%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDUzMjMzMTA3MjA0MSIMgyRhHSUjzOS%2BIvmEKu0DeeFYWUquMF04dZEmYlvlth7Yxa1KCSShdpBBtkQbCHasG3VCzOXhUsxRYwg%2BDFoSJGyo1UhluIBv1HjH6nexn7rYFNicvZ1%2Bukg1wjfmbiD%2BeFaYSmh19rw6f3IYk%2BecyVXkxBUTSuyO27jcfM3jaIUqdwcJHD60B9vFZ4j3jTLE4H1n6eCKSfZt7V23gMr6agzujSmEZC%2F7jchd8d3J%2Br360QC0UvZ4hosIaDmSGJmiUTKfrAaeOeie78IClIhYPrmOy8oI3fzFyhKekz8uNUqq74eaZvw%2F3vw%2Fv4SiPyU0cZmFv0%2BdGDPoqUGgxxWSfRi6he%2FmoGzXxbhFfeBmbFKpq8OgDILV8CTbFZfuxr9FVoxBl0E2%2FOmDmYOlW5Hn1f5R%2BCx7AY%2F2lrL0A%2FNkIlTODh9bCXWRcrzqkqc3vYh7FHk4g%2Bj5rrYkdFiBX836FSVaDFlxiIqPL4XQkKCtBgK%2BVJrKsQDXcc4dPQkv8B9yUXC2HpFz3LH1RuihfjA46aBWWNkf8AuCH%2BenGOMkKlAkiSDSinh49vb4yDNHGJNpfIH%2FjieEfY%2BtiAcn0E5glSxzaW%2BMvM6Ct3gtphhg1W5S1ICRsDzpHUExmkW4qDc8TlA3DO%2BEj0KsfkpnAdYsQeshY6BbqkDJfZD5NjChpN6zBjqmAbhaFHsiS7tBtLL7xVmK7WcaE4KN9Lon%2BZPVuNmDf7%2B4Or%2B7S5NyTx6wXhCAYILzaXQdzZMPNXyX54LAbxXoxosOyZfS7VIT4uUAJ28uLIdHGKV4pXrR9ZJvCsOiWDb0NORdgoWmqPQJ9snwOCpkaNrhhDDz382sOhQugKPxYUM98mHjxDwcDNH1n8bXSCCdEIqLbenwxYjObkvM3uTvc1nPPxHe9kM%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAXX4LHRIUUJXW7X6P%2F20240623%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20240623T032933Z&X-Amz-SignedHeaders=host&X-Amz-Expires=1800&X-Amz-Signature=1021bf05ef002a78cbee9633c03b0cc5948c7e06225685dd2493c5b786707374) |
図表3 |
![214372-3.gif](https://s3-agre-content.s3.ap-northeast-1.amazonaws.com/assets/images/seika_chart/214372-3.gif?X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDmFwLW5vcnRoZWFzdC0xIkcwRQIhAOy5T26HbvG3Qzv6ZzSfQ2QDOKXziQ9CiSqF%2BxoLby79AiApIgn7rpdxe51pnKHNLbT1RdlFS03IbEyK%2F0jThFksqCqZBAiE%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDUzMjMzMTA3MjA0MSIMgyRhHSUjzOS%2BIvmEKu0DeeFYWUquMF04dZEmYlvlth7Yxa1KCSShdpBBtkQbCHasG3VCzOXhUsxRYwg%2BDFoSJGyo1UhluIBv1HjH6nexn7rYFNicvZ1%2Bukg1wjfmbiD%2BeFaYSmh19rw6f3IYk%2BecyVXkxBUTSuyO27jcfM3jaIUqdwcJHD60B9vFZ4j3jTLE4H1n6eCKSfZt7V23gMr6agzujSmEZC%2F7jchd8d3J%2Br360QC0UvZ4hosIaDmSGJmiUTKfrAaeOeie78IClIhYPrmOy8oI3fzFyhKekz8uNUqq74eaZvw%2F3vw%2Fv4SiPyU0cZmFv0%2BdGDPoqUGgxxWSfRi6he%2FmoGzXxbhFfeBmbFKpq8OgDILV8CTbFZfuxr9FVoxBl0E2%2FOmDmYOlW5Hn1f5R%2BCx7AY%2F2lrL0A%2FNkIlTODh9bCXWRcrzqkqc3vYh7FHk4g%2Bj5rrYkdFiBX836FSVaDFlxiIqPL4XQkKCtBgK%2BVJrKsQDXcc4dPQkv8B9yUXC2HpFz3LH1RuihfjA46aBWWNkf8AuCH%2BenGOMkKlAkiSDSinh49vb4yDNHGJNpfIH%2FjieEfY%2BtiAcn0E5glSxzaW%2BMvM6Ct3gtphhg1W5S1ICRsDzpHUExmkW4qDc8TlA3DO%2BEj0KsfkpnAdYsQeshY6BbqkDJfZD5NjChpN6zBjqmAbhaFHsiS7tBtLL7xVmK7WcaE4KN9Lon%2BZPVuNmDf7%2B4Or%2B7S5NyTx6wXhCAYILzaXQdzZMPNXyX54LAbxXoxosOyZfS7VIT4uUAJ28uLIdHGKV4pXrR9ZJvCsOiWDb0NORdgoWmqPQJ9snwOCpkaNrhhDDz382sOhQugKPxYUM98mHjxDwcDNH1n8bXSCCdEIqLbenwxYjObkvM3uTvc1nPPxHe9kM%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAXX4LHRIUUJXW7X6P%2F20240623%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20240623T032933Z&X-Amz-SignedHeaders=host&X-Amz-Expires=1800&X-Amz-Signature=2f3cde35ef3736db2da3ced8b53c6df7c648386c3fc43c6c044595e99bf395b6) |
図表4 |
![214372-4.gif](https://s3-agre-content.s3.ap-northeast-1.amazonaws.com/assets/images/seika_chart/214372-4.gif?X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDmFwLW5vcnRoZWFzdC0xIkcwRQIhAOy5T26HbvG3Qzv6ZzSfQ2QDOKXziQ9CiSqF%2BxoLby79AiApIgn7rpdxe51pnKHNLbT1RdlFS03IbEyK%2F0jThFksqCqZBAiE%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDUzMjMzMTA3MjA0MSIMgyRhHSUjzOS%2BIvmEKu0DeeFYWUquMF04dZEmYlvlth7Yxa1KCSShdpBBtkQbCHasG3VCzOXhUsxRYwg%2BDFoSJGyo1UhluIBv1HjH6nexn7rYFNicvZ1%2Bukg1wjfmbiD%2BeFaYSmh19rw6f3IYk%2BecyVXkxBUTSuyO27jcfM3jaIUqdwcJHD60B9vFZ4j3jTLE4H1n6eCKSfZt7V23gMr6agzujSmEZC%2F7jchd8d3J%2Br360QC0UvZ4hosIaDmSGJmiUTKfrAaeOeie78IClIhYPrmOy8oI3fzFyhKekz8uNUqq74eaZvw%2F3vw%2Fv4SiPyU0cZmFv0%2BdGDPoqUGgxxWSfRi6he%2FmoGzXxbhFfeBmbFKpq8OgDILV8CTbFZfuxr9FVoxBl0E2%2FOmDmYOlW5Hn1f5R%2BCx7AY%2F2lrL0A%2FNkIlTODh9bCXWRcrzqkqc3vYh7FHk4g%2Bj5rrYkdFiBX836FSVaDFlxiIqPL4XQkKCtBgK%2BVJrKsQDXcc4dPQkv8B9yUXC2HpFz3LH1RuihfjA46aBWWNkf8AuCH%2BenGOMkKlAkiSDSinh49vb4yDNHGJNpfIH%2FjieEfY%2BtiAcn0E5glSxzaW%2BMvM6Ct3gtphhg1W5S1ICRsDzpHUExmkW4qDc8TlA3DO%2BEj0KsfkpnAdYsQeshY6BbqkDJfZD5NjChpN6zBjqmAbhaFHsiS7tBtLL7xVmK7WcaE4KN9Lon%2BZPVuNmDf7%2B4Or%2B7S5NyTx6wXhCAYILzaXQdzZMPNXyX54LAbxXoxosOyZfS7VIT4uUAJ28uLIdHGKV4pXrR9ZJvCsOiWDb0NORdgoWmqPQJ9snwOCpkaNrhhDDz382sOhQugKPxYUM98mHjxDwcDNH1n8bXSCCdEIqLbenwxYjObkvM3uTvc1nPPxHe9kM%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAXX4LHRIUUJXW7X6P%2F20240623%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20240623T032933Z&X-Amz-SignedHeaders=host&X-Amz-Expires=1800&X-Amz-Signature=0e84a8081623a3b00ec81d227474324e0a8f35dcb1e4bd319adc649757bfb8f1) |
図表5 |
![214372-5.gif](https://s3-agre-content.s3.ap-northeast-1.amazonaws.com/assets/images/seika_chart/214372-5.gif?X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaDmFwLW5vcnRoZWFzdC0xIkcwRQIhAOy5T26HbvG3Qzv6ZzSfQ2QDOKXziQ9CiSqF%2BxoLby79AiApIgn7rpdxe51pnKHNLbT1RdlFS03IbEyK%2F0jThFksqCqZBAiE%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDUzMjMzMTA3MjA0MSIMgyRhHSUjzOS%2BIvmEKu0DeeFYWUquMF04dZEmYlvlth7Yxa1KCSShdpBBtkQbCHasG3VCzOXhUsxRYwg%2BDFoSJGyo1UhluIBv1HjH6nexn7rYFNicvZ1%2Bukg1wjfmbiD%2BeFaYSmh19rw6f3IYk%2BecyVXkxBUTSuyO27jcfM3jaIUqdwcJHD60B9vFZ4j3jTLE4H1n6eCKSfZt7V23gMr6agzujSmEZC%2F7jchd8d3J%2Br360QC0UvZ4hosIaDmSGJmiUTKfrAaeOeie78IClIhYPrmOy8oI3fzFyhKekz8uNUqq74eaZvw%2F3vw%2Fv4SiPyU0cZmFv0%2BdGDPoqUGgxxWSfRi6he%2FmoGzXxbhFfeBmbFKpq8OgDILV8CTbFZfuxr9FVoxBl0E2%2FOmDmYOlW5Hn1f5R%2BCx7AY%2F2lrL0A%2FNkIlTODh9bCXWRcrzqkqc3vYh7FHk4g%2Bj5rrYkdFiBX836FSVaDFlxiIqPL4XQkKCtBgK%2BVJrKsQDXcc4dPQkv8B9yUXC2HpFz3LH1RuihfjA46aBWWNkf8AuCH%2BenGOMkKlAkiSDSinh49vb4yDNHGJNpfIH%2FjieEfY%2BtiAcn0E5glSxzaW%2BMvM6Ct3gtphhg1W5S1ICRsDzpHUExmkW4qDc8TlA3DO%2BEj0KsfkpnAdYsQeshY6BbqkDJfZD5NjChpN6zBjqmAbhaFHsiS7tBtLL7xVmK7WcaE4KN9Lon%2BZPVuNmDf7%2B4Or%2B7S5NyTx6wXhCAYILzaXQdzZMPNXyX54LAbxXoxosOyZfS7VIT4uUAJ28uLIdHGKV4pXrR9ZJvCsOiWDb0NORdgoWmqPQJ9snwOCpkaNrhhDDz382sOhQugKPxYUM98mHjxDwcDNH1n8bXSCCdEIqLbenwxYjObkvM3uTvc1nPPxHe9kM%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ASIAXX4LHRIUUJXW7X6P%2F20240623%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20240623T032933Z&X-Amz-SignedHeaders=host&X-Amz-Expires=1800&X-Amz-Signature=2c4f0b54b7e0ed6c69e8fc0e9f809cc577cc87e8dbc1504beb7c4cd21c99a3f5) |
カテゴリ |
育苗
水稲
施肥
播種
品種
水管理
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