Malheur Experiment Station Information for Sustainable Agriculture

Hail is a potential threat during every crop season. Pumpkin and squash growers and the crop insurance industry are interested in having an accurate method for estimating crop loss due to hail. This trial evaluated one pumpkin and two squash varieties for their response to simulated hail damage that resulted in 75 percent defoliation, before or after fruit set.

The field received 30 lb N/ac, 143 lbs P₂O₅/ac, and 6 lbs Zn/ac the previous fall and the field was plowed and disked.

Howden pumpkins, Table Ace acorn squash, and Waltham butternut squash were planted on May 18, 1994 with two seeds at 18-inch spacing in rows 12 feet apart using a Model 900 Mulch Planter (Mechanical Transplanter Co, Holland, Michigan). Replanting was done in spots with low stand on May 28.

The experiment was designed with three replicates each containing nine plots. Each plot was 30 feet long and one row wide. The rows were 12 feet apart to allow access for hail treatments. Each plot contained either pumpkins, butternut squash, or acorn squash and received either no hail, early hail, or late hail. The varieties and treatments within each replicate were completely randomized.

The hail treatments consisted of a non-hailed check treatment, simulated hail before fruit set, and simulated hail after fruit set (Table 1). The early date before fruit set was June 28 and the dates after fruit set were July 21 or August 4. Butternut squash were not hailed on July 21 since there was not yet any fruit set. Each plot in each hail treatment received hail only once. The hail treatments consisted of cubed ice being blown through a flexible plastic tube until approximately seventy-five percent of the leaf cover was removed.

Before the hail was applied, observations on plant development were made and recorded including plant width, height, and fruit size. Vines were turned back into each 30 ft by 12 ft plot on July 21, August 4, August 11, and August 22.

The crops were irrigated as needed in a single furrow down one side of the each row. Weeds were controlled by preplant application and incorporation of Prefar at 5 lbs ai/ac, by two cultivations, and by three quick hand weedings of only the planted row.

The pumpkins were harvested October 15-23 and the squash were harvested from September 25 through October 9. All of the sound fruit were harvested regardless of defects or imperfect maturity. Each fruit was weighed and graded individually. Fruit was graded into five groups: perfect, minor defects, major defects, cull and immature. Fruit with minor defects were considered to be scratches and hail damage that might be overlooked by a consumer. Fruit with minor defects and perfect fruit were considered marketable.

No hail or major cause of leaf damage occurred during the 1994 season. Growing conditions were favorable for high yields of good quality fruit.

Variety differences in yield and grade

Howden pumpkins were more productive than Table Ace acorn squash or Waltham butternut squash averaging 65,453 lb/ac total yield (Table 2); however the pumpkins also had more fruit with minor and major defects than either squash variety. The pumpkins averaged 18.94 lbs each, Table Ace acorn squash weighed 1.84 lbs each, while Waltham butternut squash averaged 2.98 lbs.

Hail Treatments

Simulated hail treatments produced significant reductions in perfect fruit (Figure 1), marketable yield (Figure 2), total yield (Figure 3), and percent marketable yield (Figure 4). Hail treatments were associated with significant increases in major defects in pumpkins, especially the late hailed pumpkins (Table 2).
 

Table 1. Timing of simulated hail on pumpkins and squash planted May 18, 1994 at Ontario, Oregon.

Treatment number		Hail treatment		Plant growth stage at hail
	Variety		Defoliation	Fully expanded	Plant height	Plant width	Average fruit length	Range of fruit length
			%	leaves	inches	inches	inches	inches
1	Howden pumpkin	Check	0	--	--	--	--	--
2		June 28	75	7	14	24	na	na
3		July 21	75	--	28	132	4	2-8
4	Table Ace acorn squash	Check	0	--	--	--	--	--
5		June 28	75	6	12	19	na	na
6		July 21	75	--	25	72	2	0-4
7	Waltham butternut squash	Check	0	--	--	--	--	--
8		June 28	75	6	6	14	na	na
9		August 4	75	--	18	192	4	0-8

Table 2. Yield and grade, marketable fruit by weight, and average marketable fruit weight of pumpkins and squash subjected to simulated hail damage, Ontario, Oregon, 1994.

		Yield by grade						Marketable yield §	Percent marketable	Average marketable fruit weight
Variety	Hail timing	Perfect fruit	Minor defects	Major defects	Culls	Immature	Total yield
		lbs/acre							%	lbs
Howden pumpkin	None	44,970	17,802	450	769	4,573	68,564	62,772	91.55	18.53
	Early	39,940	15,257	3,250	3,431	11,568	73,445	55,197	75.15	19.83
	Late	14,890	20,755	8,461	4,546	5,729	54,381	35,645	65.55	18.46
	Average	33,267	17,938	4,054	2,915	7,290	65,463	51,205	77.42	18.94
Table Ace acorn squash	None	29,269	1,093	211	150	2,870	33,593	30,362	90.38	1.91
	Early	20,174	4,065	199	444	2,718	27,600	24,238	87.82	1.78
	Late	18,923	3,406	250	459	2,346	25,383	22,329	87.97	1.82
	Average	22,789	2,855	220	351	2,645	28,859	25,643	88.72	1.84
Waltham butternut squash	None	33,967	980	961	1,640	2,375	39,922	34,947	84.08	2.98
	Early	22,716	1,149	931	898	3,940	29,634	23,865	81.45	2.97
	Late	15,301	2,473	1,420	1,751	7,006	27,950	17,774	53.97	2.98
	Average	23,995	1,534	1,104	1,430	4,440	32,502	25,529	73.17	2.98
Averages	None	36,069	6,625	541	853	3,273	47,360	42,694	88.67	7.81
	Early	27,610	6,824	1,460	1,591	6,075	43,560	34,433	81.46	8.19
	Late	16,371	8,878	3,377	2,252	5,027	35,905	25,249	69.16	7.75
LSD (0.05)Variety		6,287	4,509	986	1,860	ns	6,321	6,482	7.64	1.48
LSD (0.05)Hail		6,287	ns	986	ns	ns	6,321	6,482	7.64	ns
LSD (0.05)Variety X Hail		10,889	ns	1,707	ns	ns	ns	ns	ns	ns

^§ Perfect fruit plus fruit with minor defects

Home

Crops

Weather

Potato Blight

Water Quality

Irrigation

Weeds

Search

MES Publications, MES Notice of events, Vegetation,Malheur County, Leslie Gulch,Succor Creek,Owyhee River,Local wildlife,Strawberry Mountain, Eagle Caps

Malheur Agricultural Experiment Station

Last updated  Tuesday July 30, 2002 .