Summaries of Articles
Overview - Tomatoes
“Hydroponic Tomatoes: The Complete Guide to Soilless Success
Part Two: Production Systems and Crop Management” by Lynette Morgan,
PhD 2003, The Growing Edge 15(1), pp 60-73 - Summaries (in pdf) (html)
This is the second in a series published in the popular magazine The Growing
Edge (Corvallis, OR). The author, Dr. Lynette Morgan, is a regular contributor
to the magazine and is a horticultural consultant who holds a PhD in vegetable
production from Massey University in New Zealand. Although her perspectives
on greenhouse culture, markets, and cultivar selection are slightly different
from what we might experience in Tennessee, she writes for an American
audience and the basic science and production issues she addresses are
universal.
Overview - Strawberries
“Out-of-Season Greenhouse Strawberry Production in Soilless
Substrate”
F. Takeda 1999, Advances in Strawberry Research. Volume 18, pp 4-15. Summaries (in pdf) (html)
Fumiomi Takeda is a researcher with the Agricultural Research Service
at the Appalachian Fruit Research Station in Kearneysville, WV. His focus
is small fruit production, and he has been publishing technical papers
on greenhouse strawberries for many years. This paper provides a good
overview of the strawberry production in protected agriculture
EC and Tomatoes
“Influence of electric conductivity management on greenhouse tomato
yield and fruit quality” M. Dorais, A.P. Papadopoulos, A. Gosselin
2001, Agronomie 21, pp 367-383. Summaries (in pdf) (html)
This paper comes out of the highly respected Greenhouse and Processing
Crops Research Center under the umbrella of the Agriculture and Agri-Food
Canada in Harrow, Ontario. Dr. Papadopoulos has been publishing very applied
and reliable papers on hydroponic crops for many years, and this paper
is yet another excellent source of information. The issue of Electrical
Conductivity (EC) management and its effect on yield and quality is a
hot topic. This lengthy literature review paper explores how high ECs
cause fruit size to decrease while increasing the dry matter content.
This means that the average fruit is smaller, but may have a higher carbohydrate
content (and therefore, more sugars) than fruits from plants grown under
lower fertilizer EC regimes.
EC levels affect yield and fruit quality differently depending on how
the fertilizer solution interacts with other factors. These other factors
include the specific tomato variety being grown, various environmental
parameters such as humidity and temperature, the composition of the nutrient
solution and specific crop management strategies. Some studies showed
that ECs above 2.3 to 5.1 mS/cm reduced yield to an unacceptable level,
while at the same time, ECs of 3.5 to 9.0 mS/cm improved tomato fruit
quality. Manipulating the environmental conditions such as humidity, temperature
and ambient CO2 levels might offset some negative effects on yield and
quality issues, such as blossom end rot (BER).