Dry Farming Trails - Results

2022 Dry Farming Trial Results

DG gardeners continued experimenting with growing a variety of vegetables without any inputs of fertilizer or water after planting. Before planting, the soil was well watered and plants watered in. 

Four varieties of tomatoes, three winter squash, three summer squash and three melon varieties were planted along with five varieties of dry beans.  Over 394 pounds were harvested.  The Big Beef tomato produced the highest yield (49 pounds) of the tomatoes, and the Coast Romanesco zucchini produced the highest yield (31.5 pounds) among the summer squash varieties. 

The biggest challenges encountered were initial establishment of the melons, invasion of squash bugs and determining the ripeness of the watermelon.  The best surprises were the excellent flavor of the melon, in particular the D'Artangnan Charentais variety.

Here are some preliminary results from the 2022 Dry Farm area: 

2021 Dry Farming Trial Results

We planted 10 different varieties that had done well in previous dry farm situations and had low levels of blossom end rot.  Three of the varieties had both grafted and ungrafted plants and were the main focus of the trial.  Three varieties were hanging storage tomatoes - Mala Cara, Piennolo del Vesuvio, and Petit de Ramallet.  Plants were watered only once, when they were planted on May 25; all survived and produced fruit.

Ripe or nearly ripe tomatoes were harvested every Monday.  Harvest peaked at the end of August.  By Oct 11, only green tomatoes remained on the vines, at which time they were all harvested and donated.

Differences in Varieties: In line with expectations, the grafted individuals of any one variety produced more (weight-wise) than the ungrafted individuals.  The hanging tomatoes had quite small fruit so that the total weight harvested was generally less than the other varieties.

Soil Moisture: Moisture sensors were installed at 4 depths in the dry farm area in 2019 and were used in 2021 to take soil moisture readings periodically.  Lower numbers indicate more soil moisture and higher numbers indicate less.  Moisture was lowest (highest readings) in early September at all depths.  Following more frequent rain later in September, the shallowest meter readings began to drop.  Soil moisture at deeper depths will take longer to replenish.

Taste Testing: Eight varieties were tasted by 12 MGs at the garden in August. Each MG rated the tomato from 1-5 (with 5 the best).  Ratings were summed and divided by 12 for each final score.  Despite hearing that dry farm tomato flavor is often superior to the flavor of irrigated tomatoes, we concluded that none of these varieties had great fabulous taste compared to varieties such as Sungold or other super sweet varieties.

Blossom End Rot (BER) : We recorded Blossom End Rot on 7varieties but only 4 (Astrakan, Baylor Paste, Mala Cara, and Teardrop) had rates above 3% of the total ripe tomatoes harvested.  Much more damage was seen from rodent feeding, cracking/splitting, sunburn, and catface.

Heat And Disease Damage : Following the “heat dome” in late June, we made a heat damage assessment (plants rated 0, 1, 2, or 3 for no damage to high damage).  Two plants (of 41) showed a low amount of damage and 1 fruit on another plant had typical heat damage.  Subsequent growth and fruit production were not visibly affected, demonstrating that healthy dry farm tomatoes tolerated high temperatures extremely well.  

In mid- to late-July, powdery mildew infected most of the plants, killing much of the lower foliage and causing stem lesions with visible fungal growth. Only a couple varieties (Mala Cara and Piennolo del Vesuvio) had few or no symptoms.  Frequent high humidity at night and in the morning over a couple of weeks likely promoted infection.  Although no plants died and fruit was not infected, loss of infected foliage exposed fruit to the sun so that a lot of sunburn and heat damage was seen in subsequent weeks.