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--- tutorials:radiation-model-in-crop_model9 [2025/10/31 13:49] – barley1965
+++ tutorials:radiation-model-in-crop_model9 [2025/10/31 14:11] (current) – barley1965
@@ Line 97: / Line 97: @@
 </code>
 This bidirectional transport follows the concentration gradient between successive internodes.
 **c) Internode to Fruit Transport** (L. 269-275):
@@ Line 110: / Line 110: @@
 }
 </code>
+This final rule expresses transport in only one direction, i.e. fruits are //absolute sinks// (which is wrong, because young fruit are often green and have been shown to carry out photosynthesis).
 ===== Fruit Set Decision Based on Sugar Availability =====
-The model now makes fruit formation dependent on available sugar in the plant (L. 165-172):
+The model now makes fruit formation dependent on sugar available in the nearest leaf (L. 169-174):
 <code java>
-fl:Flower(t, m), (t >= m) ==>
+fl:Flower(t, m), (t >= m && t<m+2) ==>
-    {float sugar = sum((* lf:Leaf *)[as]);
+		{float sugar = first((* Leaf *)[as]);
-    println(sugar);
+		println("sugar: " + sugar);
-    }
+		}
-    if(probability(0.6)) (Fruit(0.01,1,0.1))
+		if(sugar>0.0005) ({noFrts++;} Fruit(0.01,1,0.1,noFrts))
-    else if(probability(0.4)) ();
+		else (fl);
 </code>
+Note that a ''Flower'' that has not yet become a ''Fruit'', has two more chances to become one.
-Sugar availability is calculated by summing all leaf assimilates before deciding on fruit formation.
+Availability of sugar is calculated by querying ''as'' of the nearest ''Leaf'' before deciding on fruit formation.
 ===== Fruit Growth Competition =====
-Multiple fruits compete for available resources using an age-based weighting system (L. 209-225):
+Multiple fruits compete for available resources using an age-based weighting system (L. 214-226):
 <code java>
 fr:Fruit ::> {
@@ Line 140: / Line 141: @@
     float sugar = (totalAgeWeight > 0) ?
         (totalSugar * ageWeight) / totalAgeWeight : totalSugar / fruitCount;
-</code>
+    </code>
-Younger fruits receive proportionally more resources through exponential age weighting, simulating their stronger sink strength.
+Younger fruits receive proportionally more resources through exponential age weighting, simulating their stronger sink affinity (thereby compensating their smaller size).
 ===== Visual Feedback =====
@@ Line 151: / Line 152: @@
 ===== Tasks for Exploration =====
-.	Run the model and observe sugar flow: Watch how internodes change color as sugar moves through them.
+  - Run the model and observe sugar flow: Watch how internodes change color as sugar moves through them.
-.	Modify DIFF_CONST: Try values between 0.0001 and 0.01. How does this affect:
+  - Modify DIFF_CONST: Try values between 0.0001 and 0.01. How does this affect:
-o	Speed of sugar movement?
+  *     Speed of sugar movement?
-o	Final fruit size?
+  * 	Final fruit size?
-o	Number of successfully developed fruits?
+  * 	Number of successfully developed fruits?
-.	Change transport frequency: Modify the condition if(time % 24 == 0) to different values (e.g., % 12 for twice-daily transport). What impact does this have?
+  - Change transport frequency: Modify the condition if(time % 24 == 0) to different values (e.g., % 12 for twice-daily transport). What impact does this have?
-.	Adjust maintenance respiration: Change MR from 0.01 to 0.05. How does increased respiration affect fruit development?
+  - Adjust maintenance respiration: Change MR from 0.01 to 0.05. How does increased respiration affect fruit development?
 ===== Biological Relevance =====